The proposed research consists of epidemiologic studies of blood pressure in the population of Tecumseh, Michigan. Their purposes are: 1) to identify predictors of blood pressure level and risk factors for high blood pressure, 2) to assess the contribution of blood pressure as a risk factor for coronary heart disease, stroke and other cardiovascular and non-cardiovascular diseases and death from all causes, 3) to identify patterns of familial aggregation and resemblance in blood pressure, change in blood pressure and occurrence of blood pressure related disease and to determine the contribution of genetic and environmental variability to blood pressure variability within and among families. Available information collected over the past 15 years on over 9000 white males and females of all ages will be used. Personal, familial and environmental characteristics which have been ascertained include demographic and socio-economic characteristics, physical and physiological measurements, genetic markers, personal habits, previous and current symptoms and disease and reproductive histories, family composition and familial morbidity and mortality. These factors will be related to concurrent and subsequent blood pressure and risk factors for high blood pressure will be identified. Predictive accuracy will be assessed and an index of risk for high blood pressure will be developed. The course and consequences of high blood pressure in a natural community will be described and measured in terms of persistence and remission of high blood pressure, onset of cardiovascular conditions and survival or death from all causes. Factors influencing the course of disease will be identified. Contributions of genetic and environmental variation of blood pressure variability will be assessed through the contrasts of covariation among related and unrelated individuals living together and living apart in this community.